Conservation of Historic Thangkas
Process of a Conservation using the example of a 200 year-old Hevajra Thangka
Hevajra Thangka before conservation
Hevajra Thangka vor der Restaurierung

Hevajra is relatively easy to recognize, because he is holding a white skull in each of his sixteen hands.

Hevajra is the most important archetype deity of the Sakya Order. The Hevajra Tantra is considered the basic Mother tantra, and its contemplation is particulary excellant in creating the conditions for the blazing of the inner fury-fire [Tib.: tummo] so important to Himalayan yogis, such as Milarepa.

Encountering Hevajra Buddha, one recalls the Shiva Nataraja in Hindu iconography, but in Buddhism there is no question of destroying the living universe - only the world of egoistic suffering should be consumed in the supernova flames.

Special iconographic feature of this scroll painting.


Condition of the scroll painting before conservation

Zustand des Rollbildes vor der RestaurierungIn former times rainfall in the Himalayan region was low.

In recent years changes in climate have brought increasing heavy downpours of rain and this has seeped through the flat clay roofs of old monasteries causing damage not only to the interior structure of monasteries but also artefacts inside.

The old mineral paints used are not water resistant and thus water damage has caused colour loss and defects to the thangka. Rainwater seepage has caused damage on a vertical axis about 10cm wide in the centre of the image.


Applied Measures

In this case of the Hevajra Thangka these measures are confined to the textile parts of the scroll painting, later a Nepalese thangka-painter will do the conservation of the picture. Normally the conservation of the painted part will be done in Germany by a painting conservator with a diploma.

At the beginning an exactly fitting colored fabric was applied on the area of the largest spots of damage on the backside of the painting and then the whole surface was doubled with a silk-crepeline. The textile behind the damages forms the basis for the foundation and the retouching by the thangka specialist. Old bondings and over paintings were left in this area.



Backside with losses and old bondings
Rückseite mit Fehlstellen und alten Verklebungen

Here it becomes obvious that the damages caused by use and humidity on the back of the picture, mainly water stains and broken threads, lessen the readability of the image on the front side

The photo on the left shows an area in the central part of the picture that was particularly damaged concerning the canvas.

 


Support fabric as base for foundation and retouches
Stützgewebe als Basis für Grundierung und Retuschen des Thangkamalers

 

The brown cotton fabric applied on the backside matches the original canvas in weave and structure and therefore the picture will be perceived by the viewer, in spite of minor, none-retouched losses, as a homogeneous unity.

Later the thangka-painter will embed the foundation meticulously into major losses for the ensuing retouching.


D
oubling of the entire reverse of the painting
Doublierung der gesamten Bildträgerrückseite

 

Then the entire backside of the canvas is doubled with acrylic resin-coated, dyed silk- crepeline to stabilize also the tiny fissures and breakings. To support the painting optimally, this method would have been enough already to prevent it from further decay.

But as in this case the aim of the conservation was a supplement of the paint layer and the crepeline would probably not have withstood the foundation due to its soft and pliable fineness it was necessary to apply the more stable cotton.


Tears and losses in the veil
Risse und Fehlstellen im Schleier


Furthermore the textile framing and the veil showed old repairs with bonded gauze. In the veil these were mostly dissolved as they were too rigid and the fine silk was already beginning to break up further at the edges between the silk and the glue.


Partial doubling with crepeline
Partielle Doublierungen mit Crepeline

The damages in the veil were partially doubled with dyed silk-crepeline. This way of consolidation by coated crepeline with acrylic-resin is a purely conservative method and should protect the original from further tearing in the already damaged spots.

The tear remains visible, though, and there is no adjusting by supporting, for the decayed condition of the fine veil-silk wouldn´t allow any improvement measures by stitching.


Recently emerged damages caused by old glue patches
Alte verklebte Fehlstellen mit neuen Schäden

There were also old hardened patches of glue in the dark-blue frame. So here too the missing flexibility of the old repairs lead to further damages at the original. The borderlines between hardened and intact original is subject to strong tension which causes further tears of the silk.

The coarsest patches of glue were removed as far as possible and the losses were under laid with especially matching dyed silk and secured by stitching. It would even be preferable to preventively remove all the old repairs with glue.

But while working it soon became clear that the silk was already in such a bad shape that any removal of the repair patches would have lead to even more loss of material. Therefore each object must be checked individually as to how much support and solidity are necessary without creating further damages in the long run. So very often a sewing conservation is to be preferred to gluing as sewing guarantees more flexibility although the condition of the textile always determines the method of conservation.

Thus the measure here applied forms a compromise aiming at improving the flexibility of threads and fabric.


Saved threads by span stitches
Mit Spannstichen gesicherte Fehlstellen

 

To secure the loose threads underlaying silk was put from above through the damaged area, respectively through an open seam on the backside, and was covered with extremely fine stiches of grège-silk.


These vertical stitches at a distance of about 5mm from one another fit very well into the lightly streaky structure of the dark-blue background thus hardly being noticeable.


Weight-tubes with broken fabric
Gebrochenes Gewebe am Gewichtsschlauch

One special peculiarity of this historic thangka is two weight-tubes filled with fine sand meant to prevent any fluttering in the wind when presented outside at a religious celebration of the monastery. One of the tubes was damaged and the sand rilled out.

The inside of the tube was newly supported with fine fabrics and then refilled.

The fine textile in the lower reaches was clearly damaged by light and therefore brittle. To be added is the weight of sand and the microscopic fine friction under changing climatical conditions. As these outer factors will partly remain further on, a solid support of a combination of bonding and sewing should be the right way.


Fabric secured and tube refilled
Gewebe gesichert und Schlauch neu befüllt
So the lateral seam of the tube was cut open for some centimetres for to be able to double at first.

Then red silk was sewed serving as an extra support.

Fine span stitches were sewn over the damaged areas. The tube was refilled with new quartz sand and the seam closed by hand.


Hevajra Thangka after the textile conservation [detail]
Detail des Hevajra Thangkas nach der textilen Restaurierung

Hevajra Thangka after the textile conservation
Hevajra Thangka nach der textilen Restaurierung

The picture on the left shows the treated textile damages, not so the missing or abrased pigments yet. Clearly you can see the brown stains along the vertical centre axis.

The nest step is the restoration of the paint damages. Most time-consuming is not the touching-up of the damaged paint-layer.

Much more time is needed for the production of genuine original pigments. The aim of it all is a faithful restoral of the original image without any discernible difference between the retouching and the undamaged original.

Conservation of damaged paintwork

|
|